1. Field of the Invention
The present invention relates to a device for accommodating a cartridge having enclosed therein a disk serving as a recording medium and, more particularly, to a disk recording or playback device.
2. Description of the Related Art
Cartridges having enclosed therein a disk serving as a recording medium are well-known. FIG. 4A is a plan view of a cartridge 6 previously proposed by the present applicant, and FIG. 4B is a side elevation of the same.
The proposed cartridge is designed for use in recording or playback devices of the superresolution type. A disk 60 is rotatably held within the cartridge 6 which is made from a synthetic resin, with a shutter 63 slidably provided on the upper wall of the cartridge 6 for alternatively exposing or closing the disk 60. The cartridge 6 has a positioning cutout 61, erroneous insertion preventing cavity 64 and fitting cavity 65 which are opened on the bottom side.
The shutter 63 is biased in a closing direction by a torsion spring 67 provided inside the cartridge 6. As shown in FIG. 4B, the torsion spring 67 is inserted into the cartridge 6 through an opening 66 formed in a side wall of the cartridge 6. The shutter 63 is usually closed to prevent dust from entering the cartridge and adhering to the disk 60.
FIG. 3 is a side elevation showing a disk recording or playback device for accommodating the cartridge 6. A holder 3 to be loaded with the cartridge 6 is supported at a base end thereof by pivots 32 on one end of a chassis 1 having a turntable 7 and a pickup 70 mounted thereon. The direction of insertion of the cartridge 6 is matched with the sliding direction of the shutter 63. The cartridge 6 is inserted into the holder 3 as it is raised, with its opening 66 facing toward the right.
Projecting inward from opposite side walls of the holder 3 are support plates 30, 30 for supporting the bottom of the cartridge 6. The holder 3 is provided inside thereof with a mechanism (not shown) for opening the shutter 63. A beam is projected from the pickup 70 onto the disk 60 as exposed by opening the shutter 63. In the following description, the direction in which the cartridge 6 is inserted into the holder 3 will be referred to as the xe2x80x9cfront,xe2x80x9d and the direction in which it is discharged therefrom as the xe2x80x9crear.xe2x80x9d
The chassis 1 is provided at its front and rear ends with a first fitting pin 5 and a second fitting pin 5a fittable into the positioning cutout 61 in the cartridge 6 and the fitting cavity 65 thereof, respectively. Each of the fitting pins 5, 5a comprises a solid cylindrical prop 50 for supporting the lower wall of the cartridge 6 and a conical guide 51 projecting from the top of the prop 50.
The positioning cutout 61 and the erroneous insertion preventing cavity 61 extend forward or rearward, and the cutout 61 has a width S slightly smaller than the diameter of lower end of the guide 51 (see FIG. 4A). The positioning cutout 61 is partly opened on the front side as indicated at 62.
When the cartridge 6 is inserted into the holder 3, the positioning cutout 61 fits around the guide 51 of the first fitting pin 5, whereby the cartridge 6 is prevented from producing backlash laterally of the holder. When the holder 3 is pivotally moved down, the cartridge 6 is placed on the top of the props 50. The disk 60 is placed on the turntable 7 for recording or reproduction of signals.
FIG. 5 is a plan view in section of the holder 3 as lowered, with the pivots 32, 32 for the holder 3 directed laterally. For the sake of convenience of description, the top wall of the holder 3 is not shown. FIG. 6 is a front view of the holder 3 as seen from the direction B in FIG. 5. The support plate 30 at right has a raised end to serve as a projection 31 for preventing misinsertion. The support plate 30 at left has an aperture 33 formed in a rear end portion thereof for the second fitting pin 5a to extend therethrough.
When the cartridge 6 is inserted into the holder 3, the misinsertion preventing projection 31 fits into the erroneous insertion preventing cavity 64. Should the cartridge 6 be inserted as turned upside down, the projection 31 fails to fit into the cavity 64, so that the cartridge 6 can not be inserted into the holder 3. This indicates to the user that the cartridge 6 is erroneously inserted upside down.
However, the conventional signal recording or reproduction device has the following problem.
A minicartridge 8 which is smaller than the cartridge 6 proposed by the present applicant in front-to-rear length has recently been proposed by other manufacturers. The minicartridge 8 has enclosed therein a disk which differs in recording or playback specifications from the disk 60 in the cartridge 6 proposed by the present applicant. As indicated in a chain line in FIG. 7, the minicartridge 8 has a rearwardly recessed portion 81 formed in its front end and extending from the midportion thereof toward the right end. Furthermore, the minicartridge 8 has a positioning cavity 68 formed in a front end portion thereof for restraining the cartridge from backlashing laterally. The cavity 68 has an opening in the lower wall of the cartridge and a closed front end.
The disk within the minicartridge 8 is different from the disk 60 in the cartridge 6 in recording or playback specifications and should therefore not be inserted into the holder 3. However, if the minicartridge 8 is inserted into the holder 3 of the conventional device in error, the minicartridge 8 is accommodated in the holder 3, without the likelihood of the recessed portion 81 reaching the misinsertion preventing projection 31. Thus, the minicartridge 8 is undesirably inserted into the holder 3 despite the provision of the projection 31.
In view of the above problem, the present applicant has conceived the idea of preventing the minicartridge 8 from being inserted in error by the first fitting pin 5 for determining the position of the cartridge 6 on the chassis 1. Because the recessed portion 81 of the minicartridge 8 is recessed rearward, the minicartridge 8 fails to come into contact with the misinsertion preventing projection 31 positioned at the right end of the holder 3, whereas the minicartridge 8 comes into contact with the first fitting pin 5 on the chassis 1 at the left end of the holder 3. For this reason, an attempt is made to prevent the minicartridge 8 from being inserted into the holder 3 in error by the first fitting pin 5.
An object of the present invention is to prevent cartridges other than the regular cartridge from being inserted into the holder in error by simple means.
A fitting pin 5 provided on a chassis 1 is fittable into a positioning cutout 61 formed in a front end portion of a cartridge 6 and opened as at 62 on a front side thereof. The fitting pin 5 has a top end positioned below the path L of movement of the upper end of the opening 62 when the cartridge 6 is inserted into a holder 3 and positioned above the point X of intersection of the fitting pin 5 with the path M of movement of the lower surface of the cartridge 6.
Another fitting pin 5 comprises a prop 50 for supporting the lower surface of the cartridge 6, a guide 51 formed on a top of the prop 50 and tapered upward with a decreasing diameter and a misinsertion precluding portion 52 extending upward from a top of the guide 51 and generally orthogonal to the plane of the chassis 1.
The misinsertion precluding portion 52 is positioned on the path M of movement of the lower surface of the cartridge 6 when the cartridge 6 is inserted into the holder 3. The portion 52 has a top end positioned below the path L of movement of an upper end of the opening 62 of the positioning cutout 61 when the cartridge 6 is inserted into the holder 3.